Locking out questions

Alright, so I got a couple questions here. First is, it doesn’t seem possible from a client side to distinguish between a user being locked out and entering invalid credentials. Unless I’m missing someone a locked out user gets the same information as a user with a bad username/password. Am I wrong? Is there a way to tell the user “Hey, you’ve been locked out for x amount of time”.

The next question Is, is it possible via xmpp, to lock out a user?

Also, is it possible from the client side to see if a user is a global admin for the system? I know it’s possible to see if a user is an admin for a muc room, but I’d like to be able to see who is an admin for the entire server, so I can modify my UI for those people.